Add one_off filter when getting all notifications for a service

Added the option to filter by one_off messages to the DAO function
`get_notifications_for_service`. Previously, one-off notifications
were not returned - this has changed so that the default is for
one-off notifications to be returned. Also simplified the `include_jobs`
filter for this function.

The DAO function gets used in 3 places - for the V1 and V2 API endpoints,
which will now start to return one-off messages. It also gets used by
the admin app which needs to pass in `include_one_off=False` to the
`get_all_notifications_for_service` where we don't want one-off
notifications to show, such as the API message log page.

tests/app/dao/notification_dao/test_notification_dao.py

@@ -957,6 +957,21 @@ def test_should_return_notifications_excluding_jobs_by_default(sample_template,
     assert exclude_jobs_manually[0].id == without_job.id
 
 
+def test_should_return_notifications_including_one_offs_by_default(sample_user, sample_template):
+    create_notification(sample_template, one_off=True, created_by_id=sample_user.id)
+    not_one_off = create_notification(sample_template)
+
+    exclude_one_offs = get_notifications_for_service(sample_template.service_id, include_one_off=False).items
+    assert len(exclude_one_offs) == 1
+    assert exclude_one_offs[0].id == not_one_off.id
+
+    include_one_offs_manually = get_notifications_for_service(sample_template.service_id, include_one_off=True).items
+    assert len(include_one_offs_manually) == 2
+
+    include_one_offs_by_default = get_notifications_for_service(sample_template.service_id).items
+    assert len(include_one_offs_by_default) == 2
+
+
 def test_get_notifications_created_by_api_or_csv_are_returned_correctly_excluding_test_key_notifications(
         notify_db,
         notify_db_session,